1. Field of the Invention
The present invention pertains to fireplace heating and, more particularly, to air heating and circulating apparatus for installation within a fireplace to produce heat pumping action without requiring a blower.
2. Discussion of the Prior Art
Fireplaces are used a great deal for heating and for the pleasant ambiance produced thereby; however, fireplaces are not notorious for the wasted heat and fuel associated therewith in that not only does a great amount of heat created by the burning of fuel, such as wood, coal and the like, escape through the fireplace chimney but heat from the remainder of the house or building housing the fireplace is also exhausted through the fireplace chimney.
There have been attempts in the prior art to provide apparatus for increasing the efficiency of fireplace heating by drawing or forcing air through the fireplace to heat the air and return the heated air to the room, as exemplified by U.S. Pat. No. 2,642,859 to Brown. Such prior art apparatus, however, have suffered the disadvantages of being relatively bulky, expensive and difficult to install; and, further, such apparatus have invariably drawn air into the fireplace under a support for the burning fuel and forced the heated air out of the fireplace at a location vertically spaced from the indrawn air near the top of the fireplace. The circulation provided by such apparatus is limited, and the burning coals and ashes have tended to be massed at the rear of the apparatus tending to burn out the apparatus.
U.S. Pat. Nos. 2,828,078 to Snodgrass, 3,001,521 to Reilly and 3,240,206 to Schutt are exemplary of prior art apparatus for supplying heated air from a fireplace by means of conduits forming parts of grates or incorporating baffles and adapted to have air blown therethrough. While these apparatus provide increased circulation of hot air, they are not as efficient in preserving fuel and obtaining maximum heat from fuel as is desirable.
In order to establish a continuous flow of heated air, the prior art has normally used blowers or fans to force air through the fireplace heating apparatus; however, such blowers or fans cannot be used in locations where no electrical power or other suitable energy source is available. Accordingly, attempts have been made to construct fireplace heating apparatus in such a manner as to create a heat pumping action from the rising of heated air. These attempts, as exemplified by U.S. Pat. Nos. 1,313,085 to Greene, 1,608,745 to Holbek, 1,640,771 to Hannum, 2,359,197 to Brooks and 2,642,859 to Brown, have had the disadvantages of having relatively complex structure and relying on circulation throughout a room based essentially on vertical air flow.